You might think a man's life would be made that little bit easier if his wife gets on well with his pals. But while it might be good for the social life, it could spell disaster in the bedroom。

　　Middle-aged men whose partners get on very well with their own friends can suffer a severe loss of sex drive, a study claims。

　　Scientists say that even though these relationships are normally completely harmless, they can have a negative effect on the husband's feelings of power and masculinity。

　　The researchers looked at the health records and details of social activities of 3,000 men aged between 57 and 85. They found that men who reported problems in their sex lives were much more likely to have the same circle of friends as their wife。

　　The scientists, from the Universities of Chicago and Cornell, in New York, have labelled the problem "partner betweenness"。

　　Writing in the American Journal of Sociology, the authors said: "In such cases, a man's female partner has stronger relationships with his confidants than the man does, which can lead to him losing his self-esteem and sexual desire."

　　"In effect, partner betweenness undermines men's feelings of autonomy and privacy, which are central to traditional concepts of masculinity. This can lead to overt conflict or problems with partner satisfaction and attraction."

　　Separate figures show that as many as one in five men have a low sex drive, which is often caused by age, illness, certain medications or even lack of sleep。

　　In some cases a low sex drive can be a sign of a more serious health problem, such as heart disease or diabetes, and experts believe that a husband or wife's low libido is one of the main reasons why marriages break down。

　　据英国《每日邮报》8月10日报道，人们通常认为，如果某人的妻子与他的朋友相处融洽，这个男人会活的更轻松。虽然这样融洽关系有利于人们的社会生活，但却可能给两性关系招致灾难。

　　一项研究称，中年男子会因为妻子与自己的哥们关系铁而导致对妻子的性冷淡。

　　科学家们说，即使两者的关系完全正常且无害，这种关系也会对丈夫的男权主义情怀产生负面影响。

　　研究人员查阅了3000名年龄在57岁至85岁男性的健康记录和社会活动，结果发现，那些被记录的有性生活障碍的男性更可能与他们的妻子有相同的朋友圈。

　　来自纽约芝加哥大学和康奈尔大学的科学家把这种情况定义为“中间配偶”。

　　将这项调查发表于《美国社会学杂志》的作者写道：“在这种情况下，男性的伴侣与其朋友之间的关系可能比男性与朋友的关系更好，这样会有损男性自尊，降低其性欲。”

　　“实际上，‘中间伴侣’会威胁到男性的自主权和隐私权，而这些对传统概念上的大男子主义极为重要。这样的情况会与伴侣带来的满足感和吸引力产生冲突并引起问题。”

　　其他数据表明，五分之一的男性因年龄、疾病、特定药物和缺少睡眠而导致性冷淡。

　　在一些情况下，性冷淡可能是心脏病和糖尿病等严重健康问题的症状，专家还认为，夫妻一方的性冷淡是婚姻破裂的主要原因。